System for automatic storage and withdrawal of objects, and object transfer device used in the system

ABSTRACT

A system for the storage and retrieval of objects comprises a store area having a plurality of housing areas for object containers, and a mobile transfer device with two or more housing areas for containers within it. The device is capable, in use, of moving the containers inside and/or outside its housing areas and simultaneously transferring the objects between the containers disposed within it.

The present invention relates to systems for automatic storage andwithdrawal of objects, and was developed with particular regard to asystem for the processing of orders within an automated store operatingwith a mobile device for transferring objects.

Stores play an essential part in the activity of any business in so faras they make it possible to keep large quantities of articles on thespot, making them available when required without the need to wait forlong delivery times. In the case, for example, of a drug store within ahospital, the need to make a large number of different medicinesavailable to the patients has significantly increased the size and rangeof such stores. The management of a store is based on operations ofstorage and retrieval of the articles contained therein, and is more orless complex, depending on the size of the store itself, the variety ofarticles contained therein, and the number of operations to be carriedout. In order to satisfy this increasing requirement, human operatorshave for some time been replaced by computerised management systemsactuating automatic devices capable of moving more rapidly within astore, of optimising and rendering more secure, complex operations ofretrieval and/or storage.

In the field of management systems for the automatic storage andretrieval of articles, numerous automated stores operating with transferdevices of various types are in fact known. The principal functionswhich must be performed by such devices are those of receiving an orderfor the retrieval or the storage of one or more specific articles,verifying and selecting the area of the store in which to deposit orretrieve said articles, operating the necessary devices so that theymove to the locations established according to a particular sequence,actuating the devices so as to withdraw or deposit every article listedin the order to be dealt with and, finally, actuating the devices sothat they deposit the withdrawn articles at the outlet of the store, orreturn to the entry of the store to take up a new group of articles tobe stored.

It very frequently occurs that the stores contain articles of dimensionsand/or shapes such as to need to be grouped and stored in suitablecontainers disposed within racks. In a hospital store, for example, thedrugs contained in single-dose packages do not exceed 50% of the totalarticles, while the other packs consist of blister packs, packets,phials and the like, which must be grouped in particular containers. Inthis case, the operations of retrieval and/or storage may be furthercomplicated, in so far as the management system, in addition toidentifying an area of the store from which to retrieve the container,must move the latter into a “picking” area.

To improve understanding of the following description, a picking area isdefined as an area of the store in which a picking operation is carriedout, that is to say, an operation in which the desired article isselected from a plurality of objects contained in a first container,withdrawn from the first container and transferred to a secondcontainer.

The movement of the container from the store to a picking area clearlyincreases the times necessary for the retrieval of an article, even inthe case where automatic devices are used instead of operators, if onlyowing to the outward and return journey which the container must makefrom the rack in which it is positioned to the picking area. For solvingsuch problems, numerous different solutions are known in this field,each of which has sought to optimise in the most efficient manner thesteps listed above.

U.S. Pat. No. 3.782.564, for example, illustrates a system for thestorage and/or retrieval of articles in a store, comprising a mobileplatform equipped with a withdrawal device and two loading areas. Duringan operation of retrieval of a stored article, the platform is sent intothe store area in which a pallet containing said article is kept. Then,the platform loads the entire pallet in its first loading area and, bymeans of a transfer device, transfers the desired article into thesecond loading area. When this operation is completed, the platformreplaces the pallet in the rack and moves to another area of the storeto carry out the retrieval of a further article, or to the outlet of thestore to unload the articles withdrawn up to that moment.

The main drawback of the system illustrated in the document U.S. Pat.No. 3.782.564 lies in the fact that the platform remains locked in theretrieval position until the selected article is placed on the loadingarea and the pallet from which the withdrawal has been made is replacedin the rack. In the case where numerous retrievals of single articlesmust be made from a plurality of pallets in different areas of thestore, this operation certainly involves long operating times.

U.S. Pat. No. 3.978.995, however, illustrates a system for the automaticstorage and/or retrieval of articles comprising a plurality of verticalelevators on which move two groups of vehicles, each with a differentfunction. A first group of vehicles comprises means for the retrieval ofdrawers disposed on racks and means for the selection and withdrawal ofan article contained therein, while a second group comprises only adrawer for the temporary depositing of such articles. During an articleretrieval operation, each vehicle of the first group withdraws one ormore articles from the containers present on the racks and deposits themin one or more vehicles of the second group. Each vehicle of the secondgroup, when a predetermined number have been collected, transfers thearticles to the outlet of the store.

The main drawback of the device illustrated in the document U.S. Pat.No. 3.978.995 is that of having to pre-arrange and manage a large numberof vehicles within a store system. During a retrieval operation asdescribed above, if the withdrawals have to be carried out on aplurality of drawers, each containing also only a single object andbeing stored in areas remote from each other, the number of vehicles ofthe first and second group must increase significantly in order tosatisfy such demands. Moreover, the management software for the storebercomes notably complex because of the need to co-ordinate themovements of a plurality of vehicles, each with different functions.

It is an aim of the present invention to remedy the drawbacks of thedevices of known type, by providing an automatic system which makes itpossible to optimise and speed up the operations of storage andretrieval of objects.

A further aim of the present invention is that of producing a storesystem which is simple, economic and capable of managing largequantities of objects also in a small space.

In order to fulfil the aforesaid aims, the subject of the presentinvention is a system for the automatic storage and retrieval ofobjects, and an object transfer device used in the system as defined inthe following claims.

According to a particular characteristic of the present invention, thehandling means and the transfer means are connected in operation to acontrol unit for controlling, in use, the independent and/orsimultaneous handling of the containers and the transfer of the objects.

One of the main advantages of the present invention lies in thepossibility of being used in storage areas disposed in opposed rows andhousing object containers of standard type.

Further characteristics and advantages will become clear from thefollowing detailed description of a preferred exemplary embodiment, withreference to the appended drawings of a system for the automatic storageand retrieval of objects, provided purely by way of non-limitingexample, wherein:

FIG. 1 is a perspective view of a system for the automatic storage andretrieval of objects according to the present invention; and

FIG. 2 is a perspective view of an object transfer device used in thesystem of FIG. 1.

With reference now to FIG. 1, an object store 1 comprises a pair ofracks 10 disposed opposite and at a predetermined distance from eachother. Each rack comprises a plurality of parallel shelves 12 definingbetween them housing areas for storage containers 14, for example, butnot by way of limitation, of the drawer or box type. The whole of theshelves therefore defines a store area containing a plurality of housingareas for storage containers, each definable by two co-ordinates X, Yand by an identification parameter of the rack.

The store comprises at least one outlet area and an entry area, providedat some housing areas defined by the shelves of the racks, which can beconnected in operation to container transfer systems, such as, forexample, a conveyor belt system or a pneumatic despatch system, fortransferring the storage containers, used within the store, to furtheroperating stations, or for receiving containers to be used within thestore.

It is of course possible also to provide more outlet and entry areas,for example two or more on each rack, as well as transfer systemsdifferent from those mentioned above, without thereby departing from thescope of the present invention.

The two racks are supported at their ends by two external framestructures 20, preferably I-shaped, each comprising a top bar 22, anupright 24 and a bottom bar 26, preferably bearing on support feet 28for supporting the frame 20 and the racks 10. Connected to the framestructure 20, and in particular, although not by way of limitation, tothe pairs of top bars 22 and bottom bars 26, are devices for moving anelevator member 31, for example rotatable belts 30, preferably closed ina ring, which extend horizontally substantially over the whole length ofthe racks 10, and are actuated by motive means (not illustrated).

The elevator member 31 connected to the rotatable belts 30 of the racks10 comprises an upper carriage 32 and a lower carriage 34 and in turncomprises two vertical rails or guides 36 connected to the ends of thetwo carriages 32, 34. On the vertical rails or guides 36 is slidablymounted a platform 40, connected in operation to further actuating means(not illustrated), and comprising an object transfer device.

As illustrated in FIG. 2, the object transfer device comprises a mainstructure on which at least three housing areas 50, 52, 54 for objectcontainers are provided and which, in the non-limiting example of FIG.2, are disposed parallel to one another and have a substantiallyrectangular or in any case elongate shape in a direction orthogonal tothe racks.

Each lateral housing area 50, 52 comprises an upper portion forreceiving a container 14 and a lower portion containing containerhandling means to make it possible, as will become clearer hereinafter,to move the containers 14 inside and/or outside the housing areas 50,52, and therefore to and/or from the shelves 12 of the racks 10. Inparticular, the upper portion of each housing area 50, 52 is defined bya perimetric base surface 60 and by two lateral walls 62 which form asliding and housing surface for a container 14. The handling meanspreferably, but not by way of limitation, comprise two hydrauliccylinders 70, each with one end connected to the perimetric base surface60 and the other end connected to a lifting device 64 fixed on thebottom of the main structure. Connected to the hydraulic cylinders 70are two substantially L-shaped retrieval members 72 comprising at one oftheir ends anchorage means such as, for example, but not by way oflimitation, suction cups 74. The hydraulic cylinders 70 are connected inoperation to motive means (not illustrated), capable, in use, ofactuating them selectively in any predetermined direction.

The central housing area 54 comprises further handling means 80, forexample, rollers, or conveyor belts or handling means similar to thosedescribed above, capable of moving towards the inside and/or towards theoutside of the platform 40 object collecting containers, such as, forexample, but not by way of limitation, carriers for pneumatic despatches16.

The object transfer device further comprises picking means of generallyknown type, such as an arm movably connected to the platform andcomprising an anchorage member, for example a suction cup, at one of itsends. The picking arm is capable of withdrawing objects contained in oneof the storage containers 14 housed in one of the lateral housing areas50, 52 and depositing them in one of the collecting containers 16 housedin the central housing area 54. The picking means may of course carryout object transfer operations also between the two storage containers,and it is possible for them to comprise anchorage means different fromthose described, without thereby departing from the scope of the presentinvention.

According to a particularly advantageous characteristic of one of theembodiments of the present invention, the picking means comprise sensormeans capable of detecting and selecting a predetermined article withina storage container containing a plurality of objects. In one of theembodiments, the stored articles comprise a label on which aredisplayed, for example, but not by way of limitation, by means of barcodes, the data relating to the object itself.

The picking means, in this case, comprise an optical sensor capable ofreading such data so as to allow the withdrawal means to select thedesired object each time. In a simpler embodiment, in the case whereevery container contains the same type of object, the sensor meansdetect only the presence of the object within the storage container.

The system for automatic storage and retrieval of objects of one of theembodiments of the present invention further comprises control means,for example, but not by way of limitation, an electronic processor and adatabase for the automatic management of the storage, retrieval andgeneral operation of the entire store. In particular, the databasecomprises a plurality of data concerning the store, for example, but notby way of limitation, the number and location of the racks, the locationof the containers within the racks and the contents of each of them, orthe number of free housing areas and their location. The database may beupdated at any time, and there may be inserted into it predeterminedsequences of retrieval and/or storage in the case of retrieval and/orstorage orders recurring frequently. Optionally, the electronicprocessor may be connected to a data network, to a telephone line or todifferent means of communication via cable or without cable forreceiving and/or communicating information about the store also byremote means.

According to a further embodiment of the present invention, the internalspace of the storage containers may be sub-divided by means of separatormembers of known type into predetermined portions, depending, forexample, on the type of object stored. The information regarding suchorganisation of the interior of the containers may be inserted into thedatabase to allow the withdrawal device of the present invention toselect a predetermined object within the containers during thewithdrawal step.

In use, when an order for the retrieval of a predetermined number ofobjects contained in the store arrives at a system control station, itis inserted, manually or automatically, into the electronic processor,and the system, together with the data contained in the database,proceeds to work out a sequence of retrieval operations for processingthe aforesaid order.

By means of a checking process, the control unit ascertains that thereis an object collecting container 16 present on the platform 40 of theelevator, in particular in the central housing area 54. In the case of anegative check result, the platform 40 is sent to the entry area of thestore to load such a container 16. If the result of the check ispositive, the platform 40 is sent to the first store area, identified byco-ordinates X, Y and by the identification parameter of the rack 10, toretrieve the first object of the order being processed. Depending on thenumber of storage containers 14 associated with the objects of theretrieval order, it is possible to envisage a different sequence ofoperations to be carried out in order to process such an order.

A Single Storage Container

Once the platform 40 is positioned so that one of its lateral housingareas 52 is opposite the storage container 14, the lifting device 64raises the end of the hydraulic cylinder 70 disposed adjacent to one ofthe two racks 10 of the store 1 from which retrieval is to be effected,and the electric motor actuates the hydraulic cylinder 70 of the objecttransfer device, bringing the retrieval member 72 close to the lateralsurface of the storage container 14. When the suction cup 74 is engagedwith the aforesaid wall, the retrieval member 72 loads into the platform40 the selected container 14, sliding it on the upper surface of theperimetric portion 60. Once the storage container 14 is completelyinside the platform 40, the picking means carry out an object transferoperation, withdrawing one or more required objects from the storagecontainer 14 and depositing them within the collecting container 16.When this operation is completed, the retrieval member 72 pushes thestorage container 14 back into its housing inside the rack 12, and thelifting device 64 lowers the end of the hydraulic cylinder 70, bringingthe device into its initial state. The platform 40 is then moved to theoutlet area from the store, where the collecting container 16 is pushedtowards the transfer means in order to be sent to following operatingstations.

As an alternative to the procedure described above, and in order tooptimise further the retrieval times for an article, once the storagecontainer 14 is completely inside the platform 40, the latter is moveddirectly towards the outlet area of the store. During its travel, thepicking means carry out the aforesaid object transfer operation, andwhen the platform arrives at the outlet area the collecting container 16can be immediately pushed towards the transfer means. This operatingmode allows the retrieval system of the present invention to utilise“idle times”, that is to say, to take advantage of the time the platformtakes to move from one area of the store to another to carry out apicking operation from the retrieved container.

Two Storage Containers

Once the first storage container 14 is loaded on board the platform 40,the elevator member moves immediately towards the area of the store inwhich is housed a second container 14 containing other objects to bewithdrawn according to the order being processed. During thisdisplacement, the withdrawal means carry out an object transferoperation, withdrawing one or more required objects from the firststorage container 14 and depositing them within the collecting container16. In this way, when the platform 40 arrives at the second housing areaof the store, positioning itself with the free lateral housing area 50at the second storage container 14 to be retrieved, it is possible toload the second container 14 immediately on the platform 40. Then theplatform 40 is moved towards the outlet area of the store, and duringits travel the picking means transfer the objects from the secondcontainer to the collecting container. As before, near the outlet areaof the store the collecting container is pushed towards the transfermeans in order to be sent towards following operating stations. In thiscase also, the system uses the idle times to optimise its operation.

Two or More Storage Containers

In this case, when the second storage container 14 has been loaded ontothe platform 40, it is possible to operate according to at least twodifferent modes:

-   a) first mode: unloading in the housing area of the second container    14 the first storage container 14, and transferring to a further    store area while the picking operation is carried out on the second    container; loading a further container on the platform 40, unloading    the second container 14 in its place and transferring the platform    40 to the following store area, repeating this procedure until    completion of the order to be processed; or-   b) second mode: moving the elevator member back to the first store    area while the picking operation is carried out on the second    container; unloading the first container in its housing area and    transferring the platform to the third store area; loading the third    container on the platform and returning the second container to its    original position while the picking operation is carried out on the    third container, repeating this procedure until completion of the    order to be processed.

Each of the two modes described above has some advantages, depending onthe characteristics and dimensions of the store in which the systemoperates, and on the type of order to be processed, so much so that itcould be the same processor which establishes each time which of the twomodes to execute. The first mode (a) is particularly advantageous interms of saving time in the case where the store is of very largedimensions and the objects to be withdrawn are contained in containerslocated in store areas very distant from each other. In this case theplatform performs only once the movements from one area of the store toanother which involve substantial consumption of time and energy. On theother hand, an operating mode of this kind significantly complicates thesoftware for management of the positions of the containers within thestore, so much so that the table of allocation of the containers whichis contained in the database must be subjected to continual updating oneach new positioning of the storage containers in the shelves. Thesecond mode (b) makes it possible not to complicate the managementsoftware and may be adopted in the case of stores of small dimensions,in the case where the objects are contained in containers housed instore areas very close to one another, or in the case where the objectsto be withdrawn are in such large numbers as to render the use of longidle times necessary.

According to a particularly advantageous characteristic of one of theembodiments of the present invention, the object transfer device makesit possible, in use, to load and/or unload on the platform 40 storagecontainers 14 housed irrespectively on one of the two racks 10 disposedopposite each other. In fact, as illustrated previously, each lateralhousing area 50, 52 comprises handling devices 70 that can be loweredselectively to disappear beneath the sliding surface formed by theperimetric base surface 60 and by the two lateral walls 62. Saidlowering mechanism makes it possible to select each time which transfermember 72 to raise and actuate for retrieval, in so far as the surfaceof the perimetric portion is always free when the device in its initialstate and the housing area 50, 52 is ready to house a new container. Theuse of gripping means such as the suction cups 74, in addition, makes itpossible to retrieve and transfer by entrainment storage containers ofstandard type, such as, for example, boxes, cartons or containers ingeneral, resting directly on the shelves 12 of the racks 10, and avoidsthe use of engagement and lifting means which could complicate theaforesaid operations or which would make it obligatory to use storagecontainers of suitable shape and dimensions.

According to a further particular advantageous characteristic of one ofthe embodiments of the present invention, the store may be loadedautomatically by taking advantage of the entry area already describedpreviously. New containers full of objects to be stored may betransferred from outside to the entry area, and from there the elevatormember may position them in free housing areas, making them availablefor subsequent retrieval operations.

According to a further characteristic of the present invention, becausethe shelves of the racks define open housing areas accessible both fromthe inside and the outside of the store, the store itself may be loadeddirectly from outside, manually or by means of a further elevator memberwhich proceeds to insert object containers directly into free housingareas, making them available for subsequent retrieval operations. Thischaracteristic is particularly advantageous in the case ofmalfunctioning and/or interruption of the entire system, in so far as itrenders the storage containers equally accessible and retrievablemanually from outside.

With the principle of the invention remaining the same, the embodimentsand details of production of the present invention may of course varywidely with respect to what has been described and illustrated, withoutthereby departing from the scope of the present invention.

1. An object transfer device, comprising: a support structure withinwhich housing areas (50, 52, 54) are provided for housing objectcontainers (14, 16); picking means connected to the support structurefor transferring, in use, objects contained in the containers (14, 16);characterised in that it comprises a plurality of handling means (70,72, 74, 80) engaged with the support structure, arranged to be actuatedindependently of one another, in use, for moving the object containers(14, 16) inside and/or outside the housing areas (50, 52, 54).
 2. Atransfer device according to claim 1, characterised in that the handlingmeans and the picking means are connected in operation to control meansfor controlling, in use, the independent and/or simultaneous handling ofthe containers and transfer of the objects.
 3. A transfer deviceaccording to claim 2, characterised in that it comprises sensor meansfor selecting, in use, an object contained within a container.
 4. Asystem for the storage and retrieval of objects of the type comprising astorage area (1) having a plurality of housing areas for objectcontainers (14), characterised in that it further comprises an objecttransfer device as defined by claim
 1. 5. A method for the retrieval andstorage of objects in a system as defined by claim 4, characterised inthat it comprises the following steps in combination with one another:a) positioning the object transfer device opposite a first containerhoused in a store area; b) loading the first container into the objecttransfer device; c) moving the object transfer device opposite a furtherstore area in which is housed a further container, and simultaneouslytransferring one or more objects from the first storage container to acollecting container housed in the object transfer device; d) loadingthe further container into the object transfer device; e) unloading thefirst container into a store area; and f) repeating step c) until thetransfer of all the objects is completed.
 6. An object handling devicefor use in a system for automatic storage and retrieval of objects asdefined in claim 4, characterised in that it comprises in combinationwith one another a support structure within which housing areas (50, 52)are provided for housing at least two containers; at least two handlingdevices (70, 72) engaged with the containment structure, arranged to beactuated independently of one another, in use, for respectively movingthe object containers (14) inside and/or outside the housing areas (50,52) in different and opposed directions; anchorage means (74) connectedto the handling devices (72) arranged particularly for engaging withsaid containers (14); the housing areas (50, 52) comprising a slidingsurface (60, 62) for the containers (14) and the handling devices (70)being arranged to be selectively lowered to disappear beneath saidsliding surface (60, 62).
 7. A device according to claim 6,characterised in that the handling devices comprise actuating meansarranged to be actuated selectively, in use, in opposed and differentdirections in order to move the object containers inside and/or outsidethe housing areas.
 8. A device according to claim 7, characterised inthat the actuating means comprise a hydraulic cylinder (70).
 9. A deviceaccording to claim 8, characterised in that the gripping means comprisea suction cup member (74).